CN105717530A - Method for applying mobile base station to enhance positioning effect in network RTK - Google Patents

Abstract

The invention discloses a method for using a mobile reference station in network RTK to enhance the positioning effect. When faults such as abnormal ionospheric activities or faults in the reference station in the domain occur within the service range of the network RTK, temporarily set up a mobile reference station in the fault area. The mobile reference station without precise coordinates uses the GNSS observation data obtained by the mobile reference station to obtain and refine the atmospheric correction information of the fault area, and then correct the differential correction information broadcast by the data processing center to mobile users, thereby ensuring network RTK positioning Service accuracy and reliability, improve system availability.

Description

A Method of Using Mobile Reference Stations to Enhance Positioning Effect in Network RTK

technical field

The invention belongs to the technical field of global navigation system and positioning measurement, in particular, it relates to a method of obtaining accurate atmospheric correction information of the area where the reference station is located by using the GNSS data of the mobile reference station without knowing the precise coordinates of the mobile reference station in advance , and then enhance the positioning accuracy, reliability and availability of network RTK.

Background technique

In RTK positioning, distance-related errors including ionospheric delay and tropospheric delay are the main reasons for limiting the effective working distance of RTK positioning in double-difference mode. The network RTK technology models the error area, which greatly weakens the limitation of the distance-related error on the RTK positioning distance, so that the user's positioning distance is improved from within 10-15km of the traditional single-station RTK technology to several points of the network RTK technology. ten kilometers. However, due to the vast territory of our country, the ionospheric activity in some low-latitude areas is extremely active during the day, making the original network RTK technology unable to effectively reduce the impact of ionospheric delay on positioning, which in turn caused the original network RTK system to have abnormal ionospheric activities. Under the circumstances, it is impossible to provide users with stable and reliable positioning services. In addition, in the actual application of network RTK, the base station may not be able to use normally due to power failure, receiver failure, network interruption, geological disasters, location changes, etc. The network RTK system provides positioning services for positioning users near the station.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a method of applying mobile reference stations in network RTK to enhance positioning effect, for fault areas such as abnormal ionospheric activities within the service range of network RTK or failure of reference stations in the domain that cannot be used normally , using mobile reference stations that do not require precise coordinates to temporarily encrypt the reference station network in the fault area to obtain atmospheric delay correction information in the area, thereby ensuring the accuracy and reliability of network RTK positioning services.

The technical solution adopted in the present invention is: a method for enhancing positioning effect by using a mobile reference station in network RTK, which is characterized in that: when the network RTK service area is abnormally active due to ionospheric activity or the reference station in the domain is faulty, it cannot be used normally When waiting for a fault, a mobile reference station that does not require precise coordinates is temporarily erected in the fault area, and the GNSS observation data obtained by the mobile reference station is used to obtain and refine the atmospheric correction information of the fault area, and then correct the data that the data processing center broadcasts to mobile users. Differential correction information, so as to ensure the accuracy and reliability of network RTK positioning services, and improve the availability of the system.

As preferably, the temporary setting up of a mobile reference station without precise coordinates in the fault area is to set up a GNSS receiver at the center of the fault area, or start the GNSS receiver that has been set up in advance in this area, as a mobile reference station, the data of the mobile station The transmission adopts TCP/IP protocol, and the data format is RTCM3.2 and higher.

As preferably, the GNSS observation data acquired by the mobile reference station is to use the static measurement mode to solve the GNSS baseline between the mobile reference station and the fixed reference station, and the entire cycle between the baselines can be obtained through a period of static observation. Ambiguity and centimeter-level coordinate information for mobile reference stations.

As preferably, the GNSS baseline between the mobile reference station and the fixed reference station is solved by the mode of static measurement, and its solution formula is:

In the formula, p and q are fixed reference station and mobile reference station respectively; i and j are observation satellite and reference satellite respectively; λ is carrier wavelength; is the double-difference carrier observation value between station p, q and satellite i, j; is the double-difference pseudorange observation; is the station-satellite double difference of the geometric distance from the station to the satellite; is the double-differenced integer ambiguity; is the double-difference ionospheric delay; is the double-differenced tropospheric delay; Measurement noise for double-differenced phase observations; Measure noise for double-differenced pseudorange observations.

As a preference, the acquisition and refinement of the atmospheric correction information of the fault area is to use the GNSS observation data of the mobile reference station, the integer ambiguity, and the location information of the mobile reference station to generate more accurate ionosphere and tropospheric delay corrections in this area information.

As preferably, the ionospheric and tropospheric delay correction information is:

$\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&lsqb;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&rsqb;</span>\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}\end{array}<span\; class="notranslate">\; ;</span>$

In the formula, Indicates the station-satellite double difference; λ ₁ , λ ₂ are L1 and L2 carrier wavelengths; f ₁ , f ₂ are L1 and L2 carrier frequencies, N ₁ , N ₂ are L1 and L2 carrier integer ambiguities; φ ₁ , φ ₂ is the carrier observation value of L1 and L2; ρ is the geometric distance from the station to the satellite; Iono is the ionospheric delay; Trop is the tropospheric delay.

Preferably, the correction data processing center broadcasts the difference correction information to mobile users, and the data center adds the correction information to the calculation of the region difference correction information, and corrects the network RTK difference correction information of the region.

Compared with the existing network RTK technology, the beneficial effects of the present invention are as follows: the present invention aims at the poor positioning accuracy, low reliability and limited availability of the existing network RTK technology in areas with active ionospheric activities, and the original reference station is limited. The loss will affect the real-time positioning of users in the vicinity of the station. A new network RTK technology with a mobile reference station is proposed. This technology uses the mobile reference station to temporarily encrypt the GNSS reference station network in faulty areas such as abnormal ionospheric activities or failure of the reference station in the domain without knowing the precise coordinates of the mobile reference station in advance, shortening the distance between base stations, and Through the overall calculation, accurate ionospheric and tropospheric delay correction data can be obtained in a short time, thereby improving and ensuring the positioning accuracy and reliability of the network RTK system positioning users.

Description of drawings

Figure 1: Flowchart of the implementation of the present invention.

detailed description

In order to facilitate those of ordinary skill in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit this invention.

The present invention provides a method for using mobile reference stations in network RTK to enhance the positioning effect. A mobile reference station is set up in the center of the area, and the atmospheric correction information of the area is obtained by processing the GNSS observation data obtained by the mobile reference station, thereby improving and ensuring the positioning accuracy, reliability and availability of the network RTK system positioning users . The overall flow chart is shown in Figure 1.

Specifically include the following steps:

1) First, start the network RTK system with the mobile reference station, and carry out the normal network RTK calculation process under normal conditions to provide services for network RTK users.

2) Use the CORS-based space environment monitoring module to detect the fault area with abnormal ionospheric activity, and temporarily set up a mobile reference station in the center of the fault area; when the original GNSS reference station is damaged and cannot work normally, it can Build a mobile reference station (GNSS receiver) near the station or in the center of the field operation area. When choosing the erection location, try to choose a place with no shelter, small multipath effect, and stable ground surface.

3) The network RTK data processing center is equipped with a network port dedicated to monitoring the mobile reference station. The mobile reference station connects to the network RTK system through the TCP/IP protocol, and sends the basic GNSS observation data to the data processing center. The transmission message format is RTCM3. 2 and later.

4) When receiving the real-time data sent back from the mobile reference station in the fault area to the network RTK data processing center, the system starts to call the data processing module of the mobile reference station, selects a fixed reference station near the mobile reference station as the base station, and uses static differential The measured mode performs baseline calculation, as shown in formula (1):

In the formula, p, q are fixed reference station and mobile reference station respectively; i, j are observation satellite and reference satellite respectively; λ is carrier wavelength; is the double-difference carrier observation value between station p, q and satellite i, j; is the double-difference pseudorange observation; is the station-satellite double difference of the geometric distance from the station to the satellite; is the double-differenced integer ambiguity; is the double-difference ionospheric delay; is the double-differenced tropospheric delay; Measurement noise for double-differenced phase observations; Measure noise for double-differenced pseudorange observations.

Through static observation for a period of time, the double-difference integer ambiguity is fixed, and then the fixed ambiguity is reversely substituted into formula (1) to obtain the coordinate information of the mobile reference station.

5) After obtaining the GNSS observation data of the mobile reference station, the ambiguity of the entire circumference, and the cm-level position information of the mobile reference station, the station can be included in the GNSS reference station network, and the GNSS observation data of the station, the ambiguity of the entire circumference The ionospheric and tropospheric delay information in the area where the station is located can be calculated, such as the formula (2), and then the original atmospheric correction information can be corrected.

$\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&lsqb;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&rsqb;</span>\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}<span\; class="notranslate">\; \&dtri;</span>\mathrm{<span\; class="notranslate">\; I</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

In the formula, Indicates the station-satellite double difference; λ ₁ , λ ₂ are L1 and L2 carrier wavelengths; f ₁ , f ₂ are L1 and L2 carrier frequencies, N ₁ , N ₂ are L1 and L2 carrier integer ambiguities; φ ₁ , φ ₂ is the carrier observation value of L1 and L2; ρ is the geometric distance from the station to the satellite; Iono is the ionospheric delay; Trop is the tropospheric delay.

6) After generating accurate atmospheric correction information in the area, the system broadcasts the differential correction information required by the user to the user according to the different needs of the user. At this point, the user of the network RTK system with a mobile reference station can experience abnormal activities in the ionosphere. Or the reference station in the domain fails and cannot be used normally to complete the positioning operation in the faulty area.

It should be understood that the parts not described in detail in this specification belong to the prior art.

It should be understood that the above-mentioned descriptions for the preferred embodiments are relatively detailed, and should not therefore be considered as limiting the scope of the patent protection of the present invention. Within the scope of protection, replacements or modifications can also be made, all of which fall within the protection scope of the present invention, and the scope of protection of the present invention should be based on the appended claims.

Claims (7)

1. the method that application flowing base station strengthens locating effect in network RTK, it is characterized in that: when occur in network RTK service area in because of ionosphere activity exception or territory base station fault cannot the normally fault such as use time, at the fault zone temporary erection flowing base station without accurate coordinates, the GNSS utilizing flowing base station acquired observes data, obtain and the atmospheric correction information of this fault zone of refining, and then correction data processing centre broadcasts to the differential correcting information of mobile users, thus ensureing precision and the reliability of network RTK positioning service, the availability of raising system.

2. the method that application flowing base station strengthens locating effect in network RTK according to claim 1, it is characterized in that: described at the fault zone temporary erection flowing base station without accurate coordinates, it is set up GNSS receiver in center, fault zone, or start the GNSS receiver that this region is laid in advance, as flowing base station, the data transmission of rover station adopts ICP/IP protocol, and data form is RTCM3.2 and more highest version.

3. the method that application flowing base station strengthens locating effect in network RTK according to claim 1, it is characterized in that: the described GNSS utilizing flowing base station acquired observes data, it is that the pattern adopting static measurement resolves the GNSS baseline between flowing base station and fixed reference station, the integer ambiguity between baseline and the coordinate information of flowing reference station cm level can be obtained by the static observation of a period of time.

4. the method that application flowing base station strengthens locating effect in network RTK according to claim 3, it is characterised in that: the pattern of described employing static measurement resolves the GNSS baseline between flowing base station and fixed reference station, and its solution formula is:

In formula, p, q respectively fixed reference station and flowing base station；I, j respectively observation satellite and reference satellite；λ is carrier wavelength；For the double difference carrier observations between survey station p, q and satellite i, j；For double difference Pseudo-range Observations；Station star double difference for the geometric distance of survey station to satellite；For double difference integer ambiguity；For double difference ionosphere delay；For double difference tropospheric delay；For double difference phase observation value measurement noise；For double difference Pseudo-range Observations measurement noise.

5. the method that application flowing base station strengthens locating effect in network RTK according to claim 1, it is characterized in that: the atmospheric correction information of described acquisition this fault zone of refining, be utilize the GNSS observation data of flowing base station, integer ambiguity, flowing base station positional information to generate more accurate ionosphere, this region, tropospheric delay correction information.

6. the application flowing base station method that strengthens locating effect in network RTK according to claim 5, it is characterised in that described ionosphere, tropospheric delay correction information is:

$\mathrm{\&Delta;}\&dtri;Iono=\left(\frac{f_2^2}{f_1^2-f_2^2}\right)\&lsqb;({\mathrm{\&lambda;}}_1\mathrm{\&Delta;}\&dtri;{\mathrm{\&phi;}}_1-{\mathrm{\&lambda;}}_2\mathrm{\&Delta;}\&dtri;{\mathrm{\&phi;}}_2)+({\mathrm{\&lambda;}}_1\mathrm{\&Delta;}\&dtri;N_1-{\mathrm{\&lambda;}}_2\mathrm{\&Delta;}\&dtri;N_2)\&rsqb;;$

$\mathrm{\&Delta;}\&dtri;Trop=\mathrm{\&Delta;}\&dtri;\mathrm{\&rho;}-({\mathrm{\&lambda;}}_1\mathrm{\&Delta;}\&dtri;{\mathrm{\&phi;}}_1+{\mathrm{\&lambda;}}_1\mathrm{\&Delta;}\&dtri;N_1)-\mathrm{\&Delta;}\&dtri;Iono$

In formula,Represent double difference between the star of station；λ₁、λ₂For L1 and L2 carrier wavelength；F₁、f₂For L1 and L2 carrier frequency, N₁、N₂For L1 and L2 ambiguity of carrier in full period；φ₁、φ₂For L1 and L2 carrier observations；ρ is the survey station geometric distance to satellite；Iono is ionosphere delay；Trop is tropospheric delay.

7. the method that application flowing base station strengthens locating effect in network RTK according to claim 1, it is characterized in that: described correction data processing centre broadcasts to the differential correcting information of mobile users, it is that this correcting information is added in the calculating of this area difference correcting information by data center, corrects the network RTK differential correcting information in this region.